Answer :

To find an expression which represents the sum of [tex]\( (3x - 3) \)[/tex] and [tex]\( (-4x - 9) \)[/tex] in simplest terms, follow these steps:

1. Write down the given expressions:
[tex]\[ 3x - 3 \][/tex]
[tex]\[ -4x - 9 \][/tex]

2. Add the expressions together:
[tex]\[ (3x - 3) + (-4x - 9) \][/tex]

3. Combine like terms:
- Combine the [tex]\( x \)[/tex]-terms: [tex]\( 3x \)[/tex] and [tex]\( -4x \)[/tex]:
[tex]\[ 3x - 4x = -x \][/tex]
- Combine the constant terms: [tex]\( -3 \)[/tex] and [tex]\( -9 \)[/tex]:
[tex]\[ -3 - 9 = -12 \][/tex]

4. Write the resulting simplified expression:
[tex]\[ -x - 12 \][/tex]

Thus, the expression which represents the sum of [tex]\( (3x - 3) \)[/tex] and [tex]\( (-4x - 9) \)[/tex] in simplest terms is
[tex]\[ -x - 12 \][/tex]